At least one purpose associated with the addition of a stabilizer to a polymeric resin is to prevent deterioration of the polymers derived from the resin during processing at high temperatures and also to permit the manufacture of products with increased intrinsic quality attributable at least in part to increased resistance to thermal and light degradation during their intended use.
Many organic phosphites have been used as stabilizers, and most are based on alkylphenols. Among them are the commercially significant phosphites, tris(nonylphenyl)phosphite (TNPP) and tris(2,4-di-t-butylphenyl)phosphite. Historically, TNPP has been the primary low cost liquid phosphite stabilizer used in the plastic and rubber industry. Recently, however, plastic and rubber manufactures have been reluctant to use TNPP in their formulation due to concerns that one of the degradation product of TNPP (nonylphenol) may be xenoestrogen.
U.S. Pat. No. 6,541,549 B2 and U.S. Pat. No. 7,199,170 B2 disclose phosphite compounds having a general Structure I as non-xenoestrogenic stabilizers for polymers, although they are still based on an alkylphenol.

U.S. Pat. No. 7,186,853 B2 discloses phosphites comprising substituted or unsubstituted tricyclodecylmethyl groups. The phosphites disclosed also comprise certain alcohols which can be aliphatic, arylalkyl and alkylaryl.
U.S. Pat. No. 7,468,410 B2 and WO 07 009,916 disclose tris-(mono-alkyl)phenyl phosphites or a mixture of the general Structure II where each R is the same or different alkyl group having 1 to 8 carbon atoms. Again this is a low molecular weight monophosphite still based on an alkylphenol.
The problem with the mono phosphites or lower molecular weight phosphites described in the mentioned patents are that, the phosphites are still based on an alkylphenol of some type and lower molecular weight phosphites can be extracted easily from the polymer. Alkylphenols are of concern as potential skin irritants or having xenoestrogenic activity. Being easily extracted from a polymer means the phosphite or its degradation products can easily migrate into foods that come into contact with polymer that maybe stabilized with the lower molecular weight or mono phosphites.

WO 08 028,858 discloses liquid polymeric phosphites of the general structure III wherein L is a linkage between the repeated unit n, comprising C1-C24 alkylene, C2-C24 alkenylene, and oxygen, sulfur or substituted nitrogen (N—R) interrupted C2-C24 alkenylene. The integer m is 0 and 1.

A disadvantage of the polymeric phosphites of this disclosure is that all the polymeric phosphites are based on an alkylphenol of some type. It is preferable to have a polymeric phosphite that does not contain an alkylphenol.